package com.atguigu.gulimall.product.service.impl;

import com.atguigu.gulimall.product.service.CategoryBrandRelationService;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Resource
    private CategoryBrandRelationService categoryBrandRelationService;

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    /**
     * 查出所有分类以及子分类，以树形结构组装起来
     *
     * @return
     */
    @Override
    public List<CategoryEntity> listWithTree() {
        //先查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        //组装成树形结构
        //先找到所有的一级分类
        List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntity -> categoryEntity.getParentCid() == 0)
                .peek((menu) -> menu.setChildren(getChildrens(menu, entities)))
                .sorted(Comparator.comparingInt(menu -> (menu.getSort() == null ? 0 : menu.getSort())))
                .collect(Collectors.toList());
        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> list) {
        //TODO 检查当前删除的菜单，是否被别的地方引用
        baseMapper.deleteBatchIds(list);
    }

    /**
     * 找到catelogId的完整路径
     * [父/子/孙]
     *[2,28,255]
     * @param catelogId
     * @return
     */
    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();
        //递归查询是否还有父节点
        List<Long> parentPath = findParentPath(catelogId, paths);
        //进行一个逆序排列
        Collections.reverse(parentPath);
        return parentPath.toArray(new Long[parentPath.size()]);
    }

    /**
     * 级联更新所有关联的数据
     * @param category
     */
    @Transactional
    @Override
    public void updateCascade(CategoryEntity category) {
        this.updateById(category);
        categoryBrandRelationService.updateCategory(category.getCatId(), category.getName());
    }

    private List<Long> findParentPath(Long catelogId,List<Long> paths){
        //1、收集当前节点id
        paths.add(catelogId);
        //根据当前分类id查询信息
        CategoryEntity byId = this.getById(catelogId);
        //如果当前不是父分类
        if (byId.getParentCid() != 0) {
            findParentPath(byId.getParentCid(), paths);
        }

        return paths;
    }

    /**
     * 获取子分类
     * @param root 当前菜单
     * @param all 全部菜单
     * @return
     */
    private List<CategoryEntity> getChildrens(CategoryEntity root, List<CategoryEntity> all) {
        List<CategoryEntity> children = all.stream().filter((categoryEntity -> {
            return Objects.equals(categoryEntity.getParentCid(), root.getCatId());
        })).peek(categoryEntity -> categoryEntity.setChildren(getChildrens(categoryEntity, all))).sorted(Comparator.comparingInt(menu -> (menu.getSort() == null ? 0 : menu.getSort()))).collect(Collectors.toList());
        return children;
    }

}